It is well known in the circuit-breaker art to provide "puffer-type" cmpressed-gas circuit-interrupters in which a gas-compressing "puffer" cylinder is provided to interrelate movable contact-structure motion with the movable piston, or movable cylinder motion, for simultaneous arc establishment and gas-compression for arc interruption. Also, as well known in the art, there may be provided a movable orifice member of insulating material, or an insulating nozzle member movable with the movable contact structure, and serving the function of directing the compressed gas, ejected from the piston-and-cylinder arrangement, into the arc, the latter, of course, being established interiorly within the center of the aforesaid nozzle.
As the demands for interrupting capacity increase, requiring circuit-interrupters to be designed to accommodate the higher voltages and currents, the double-break type of circuit-breaker structure, involving two serially-related arcs, are a necessity to not only divide the voltage between the two interrupting structures, but also to intensify the gas blast directed into the two arcs. The aforesaid U.S. Pat. No. 4,075,447 issued to Rostron exemplifies such a double-break type of circuit-breaker structure.